1. Field of the Invention
The present invention relates to a drill guide device, especially a drill guide device for dental implant that can improve efficiency of fabricating a surgical stent.
2. Description of the Prior Arts
Teeth are calcified structure formed in the mouth for biting and chewing. Adult's teeth may be damaged by oral diseases or external forces, and the broken teeth are unable to regenerate. After the teeth are damaged, the alveolar bone and the gums of the mouth may be shrunk, and this may impair the eating capability. To avoid the above-mentioned problem, the common treatment is dental implant to replace the broken or lost teeth with artificial teeth.
Dental implant is done by first drilling a pilot hole in suitable size on the dental ridge of a patient, and planting an implant fixture into the pilot hole of the dental ridge. After the dental ridge is healed, an abutment is securely connected to the implant fixture, and finally a crown is mounted around the abutment to finish the implant. The crown is supported by the implant fixture and the dental ridge to sustain the forces of chewing and biting, so the eating function is regained.
The dental implant comprises multiple steps, and the first step is obtaining implantology data by computerized tomographic scan and manufacturing the gum model of a patient, the second step is drilling a hole in the gum model and producing a surgical stent. Implant site and angulation have to be confirmed by scan and modified by the dentist based on the actual diagnosis. For example, if bone under the original drill site is damaged or thin, a new drilling of the hole needs to avoid the site of the thin dental bone and move to another site with thick dental bone in consideration of the patent's teeth to bear the pressure on the vertical and horizontal directions, such that the implant fixture and the crown can sustain the biting forces from the mouth; or the dentist needs to do some bone grafting to augment the bone volume thus to keep the ideal position for restoration. It means that the appropriate drilling site, orientation and angulation are the key factors to successful dental implant.
A conventional technique for making surgical stent uses a standard rod and multiple guiders in different diameters. In the fabrication process, the dentist first drills on an implant site on the gum model according to the implantology data obtained by pre-surgical scan and computation, and mounting the standard rod into a hole drilled on the implant site. With reference to FIG. 7, the gum model is clamped securely by a surveyor 50 for confirming the orientation and elevation angle of the standard rod. The surveyor 50 has a base platform 51, a pillar 52, a horizontal arm 53, a vertical arm 54, a reference rod 55, a supporting seat 56, a universal joint 57 and a cast holder 58. The pillar 52 is mounted on and protrudes from one side of the base platform 51, the horizontal arm 53 is mounted on a top end of the pillar 52, and the vertical arm 54 is mounted through the horizontal arm 53 and corresponds to a center of the base platform 51.
The reference rod 55 is mounted on a bottom end of the vertical arm 54. The horizontal arm 53 has a first knob 531 for adjusting the height of the vertical arm 54. The vertical arm 54 has a second knob 541 for fixing the reference rod 55. The supporting seat 56 is mounted on the center of the base platform 51 below the vertical arm 54, the universal joint 57 is mounted on the supporting seat 56, and the cast holder 58 is connected to the universal joint 57. The cast holder 58 is applied to hold a gum model 60, and the universal joint 57 can be turned for adjusting the elevation angle of the cast holder 58 relative to the reference rod 55.
The elevation angle of the standard rod is measured by the surveyor 50 for confirming the orientation and elevation angle of the standard rod, and if the orientation or elevation angle of the standard rod is incorrect, the hole of the gum model has to be re-drilled and the measuring steps are repeated, which causes a complicated procedure in drilling and measuring. When the orientation and elevation angle are correct, multiple guiders are mounted on the standard rod. The number of the guiders depends on the actual diagnosis. The diameter of the biggest guider is the actual size of the hole to be drilled on the dental ridge of the patient.
Then, the gum model, the standard rod, and the multiple guiders are covered by resin. After a while, the resin is solidified to form a surgical stent. By removing the standard rod from the surgical stent, the surgical stent is mounted on the dental ridge of the patient for processing the drilling.
The conventional standard rod is mounted in the gum model, and the gum model has to be mounted securely on the surveyor for confirming the orientation and elevation angle of the standard rod, and then continuing the process of fabricating the surgical stent. As each tooth of the patient has a unique elevation angle, when a patient needs to install multiple dental implants, multiple measuring and readjusting steps are needed before mounting the standard rods into the gum model. This causes a complicated process and takes lots of time to fabricate the surgical stent. After mounting the standard rods into the gum model, the drilling site, orientation and angulation of the gum model need to be confirmed by the oral scan data of the patient. So for improving the efficiency of fabricating the surgical stent, simplifying the measuring steps is necessary.
To overcome the shortcomings, the present invention provides a drill guide device for dental implant to mitigate or obviate the aforementioned problems.